Abstract

Neutron-diffraction experiments have been performed on small single crystals of U2T2In(T=Ni,Pd,Pt) to verify the noncollinear magnetic structures found with studies of polycrystalline samples, and determine the values of the ordered moments. Compared to the earlier studies our findings agree on the structure, but find the ordered moments on the uranium atoms larger, and we fing no moment associated with the T atoms, in dizagreement with one previous study. The T=Pt sample, which is one of the most interesting of this series as it has a large electronic specific heat, does not order magnetically. We confirm the doubling of the tetragonal c-axis found first with x-ray diffraction, and give an accurate picture of the structure and the atomic coordination. All these materials appear completed ordered from a crystallographic perspective.